Dolphins are aquatic mammals known, about 50 million years ago differentiation comes from ungulates. Reporters learned from the Kunming Institute of Zoology, Chinese Academy of Sciences, the 24th system analysis by scientists dolphins genome reveals the evolution of cetaceans and their "secret into the water.

Cetaceans are the mammalian rare aquatic species, the dolphin is one of them. They are evolved from terrestrial mammals ARTIODACTYLA life back into the water around 50 million years ago.

Cetaceans "secondary into the water" event is a rare change in the life history of mammalian evolutionary history, their living habits into a fully aquatic terrestrial. The dramatic changes in the environment lead to have undergone a significant change in their physiological structure to adapt to aquatic life, such as thickening of the subcutaneous fat layer (whale oil), long time, scuba diving and echolocation ability, at the same time with a strong muscular system to support water sports. Although people have learned many physiological and morphological characteristics of adaptability, but the molecular basis of these characteristics have not been systematically addressed.

In recent years, with the rapid increase of genomic data, molecular evolution research focus to explore the genetic basis of adaptive evolution of species through comparative genomics and bioinformatics.

Kunming Institute of Zoology, Chinese Academy of Sciences academician Zhang Yaping research group the dolphin genome has announced, by comparison with the genome of other closely related species, the system identified the dolphin experience positive selection gene and the sites, to understand dolphins and other cetaceans aquatic animal to adapt to lay the foundation, but also provide clues for further study of the function of these genes.

The researchers in charge of the project, by building high-quality sequence among related species (including dolphins, cows, dogs, pandas, as well as...